This invention relates in general to certain new and useful improvements in stimulators for application of electrical stimuli pulses to an animal body, and, more particularly, to electrically operable stimulators including a unique pulse generator and output amplifier.
There are several forms of electrical stimulators which haave been proposed for the relief of pain and similar purposes including body ailment healing and accordance of certain deleterious conditions which might otherwise arise. While the underlying pathogenesis which gives rise to these results is generally not understood fully, the clinical manifestation is certain and definite. For example, it has been found that application of electrical stimuli in proximity to an incision in thoracic surgery has been found to reduce the possibility of collapsed lungs.
Generally, it has been found that when using electrical stimulation from these electrical stimulators, with terminals applied to the body, that the output current introduced to the body has a substantial effect in reducing pain sensation and producing the other effects mentioned above. With respect to pain reduction, the exact phenomena in the reduction of pain also is not fully understood, although it has been determined that substantial pain reduction can be obtained through the application of such electrical pulses.
Those commercially available stimulators presently used include, in large measure, the now out-dated tube-type stimulators, primarily found in many physical therapy operations. There has been a recent introduction into the market place of these electrically operable stimulators constructed with solid-state circuitry. However, these stimulators suffer from a number of serious drawbacks in that they are difficult to use in that the controls of these mechanisms cause the various components of the circuit to interact in a rather complex way.
It is desirable to control the pulse width and the frequency and amplitude of signal outputs from these stimulators rather carefully, in order to achieve an optimum desired effect and to eliminate any unpleasant sensations for the patient. However, the prior art devices were not relatively effective in this regard since they were difficult to control, and consequently they have not been widely accepted.
The present invention obviates these and other problems in the provision of an electrical stimulator which includes a uniquely designed pulse generator and a uniquely designed output amplifier which permits precise control and generation of a desired output signal. The stimulator of the present invention also provides a greater range of applicability due to its ability to obtain close control and very reliable repeatability.